1. Field of the Invention
The present invention relates to a neck end for a filler neck of a tank of a motor vehicle, in particular a neck end which can be closed without a cap having an entry space, which is particularly but not necessarily designed as a pipe section having a funnel or pipe-like wall, wherein the entry space can have a continuous or changing cross section of any shape. In the following, the entry space will be identified in this description as a pipe section, without this being associated with a limitation to a certain geometry.
2. Description of the Related Art
In the pipe section, the neck end has a lower sealing flap and, above the lower sealing flap, a closing mechanism, which has an upper filling opening and at least one upper cover, which at least partially covers the upper filling opening in its closed state. The closing mechanism is thereby embodied in such a manner that the upper cover is displaced by inserting an outlet pipe of a fuel nozzle into the pipe section for releasing the upper filling opening so as to allow for the insertion of the outlet pipe through the upper filling opening and the lower sealing flap. Almost throughout the world, the fuel nozzles thereby have a different pipe diameter for diesel fuels and gasoline.
Neck ends of this type are known from DE 203 09 799.8 U1. In this neck end, the neck is closed via two flaps, which are arranged on top of one another in the neck and which are held against a sealing surface by the force of, in each case, a closing spring. The two caps are pressed downward by inserting the outlet pipe of a fuel nozzle or of a spout of a jerry can, thus resulting in a continuous opening.
Even though these closures provide for a good seal, even without an additional tank cap, it would still be desired if they could be further improved and if they additionally had a protection against improper fueling. Particularly in the case of modern engines, it is increasingly important to keep in mind safe fuel grades due to the fact that, for example, modern injection systems of a common-rail diesel injection are lubricated via the lubricant content of the diesel fuel and can sustain heavy damages after being operated with a gasoline for only a short operating time.